Vitamin D deficiency does not cause disease
RESEARCHERS who conducted a large systematic review of studies on 25-hydroxyvitamin D (25(OH)D) say the association between 25(OH)D and health disorders reported in many observational studies are not causal. The research, published in The Lancet Diabetes and Endocrinology, included 290 prospective cohort studies (279 on disease occurrence or mortality, and 11 on cancer characteristics or survival), and 172 randomised trials of major health outcomes and of physiological parameters related to disease risk or inflammatory status. The researchers wrote that evidence from the review suggested that low 25(OH)D could be the result of inflammatory processes involved in the occurrence and progression of disease. They said most prospective studies reported moderate to strong inverse associations between 25(OH)D concentrations and cardiovascular diseases, serum lipid concentrations, inflammation, glucose metabolism disorders, weight gain, infectious diseases, multiple sclerosis, mood disorders, declining cognitive function, impaired physical functioning, and all-cause mortality. High 25(OH)D concentrations were not associated with a lower risk of cancer, except colorectal cancer. “Results from intervention studies did not show an effect of vitamin D supplementation on disease occurrence, including colorectal cancer … An exception would be slight gains in survival after the restoration of vitamin D deficits due to lifestyle changes induced by ageing and ill health”, the researchers wrote. They said five trials were under way testing whether vitamin D supplementation can reduce the risk of cancer, cardiovascular diseases, diabetes, infections, declining cognitive functions, and fractures. “The first results are not expected before 2017, but these studies have the potential to test our hypotheses”, they wrote. An accompanying editorial said that despite the growing body of evidence indicating that vitamin D was unlikely to prevent non-skeletal disorders, there was “strong support for its use from many prominent members of the research community, which is fuelled by the relatively low toxicity of vitamin D, the glimmer of positivity from some trials, and the large body of evidence from prospective observational studies”. However, the editorial said vitamin D might not be safe in all settings and this was a concern, given the large number of people taking vitamin D supplements.
Disadvantage linked to preterm birth
AUSTRALIAN research has demonstrated the “very strong influence” of relative socioeconomic status on preterm birth, “even in first world areas with universal health care”. The study, published in the Australian and New Zealand Journal of Public Health, examined clinical information about 836 292 births from NSW mandatory surveillance system data between 1994 and 2004. The research included 795 149 (95.08%) babies born at term and 41 143 (4.92%) who were preterm, with 33 793 (4.04%) births classified as “mildly preterm” (33‒36 weeks gestation), 4855 (0.581%) “very preterm” (29‒32 weeks) and 2495 (0.298%) “extremely preterm” (23‒28 weeks). The percentage of preterm births rose during the study period from 4.60% in 1994 to 5.27% in 2004, with the overall risk of preterm birth rising incrementally across four increasing categories of disadvantage. “Compared to mothers from the least socioeconomically disadvantaged areas, the mothers from less disadvantaged areas had an increased risk (OR 1.22, 99.67% CI 1.00-1.48) of having an extremely preterm baby, and this rose to 45% (OR 1.45, 99.67% CI 1.2-1.75) for mothers from the most disadvantaged areas. Advanced maternal age, Aboriginality, diabetes mellitus and essential hypertension were all associated with a similar dose response relationship for increasing risk of prematurity”, the researchers wrote. They concluded that, even after adjusting for year of birth and patterns of possible mediators such as smoking, medical conditions, maternal characteristics and late entry to antenatal care, “disadvantage remains a powerful determinant of preterm birth”.
Measles eliminated but threats remain
A NEW report published in JAMA Pediatrics has found the elimination of endemic measles, rubella and congenital rubella syndrome (CRS) has been sustained in the US, but an accompanying editorial has warned that parent hesitancy to vaccinate their children has emerged as a major future threat. An expert panel reviewed data from 2001 to 2011 of the US resident population and international visitors, including disease epidemiology, importation status of cases, molecular epidemiology, adequacy of surveillance, and population immunity as estimated by national vaccination coverage and serologic surveys. They found that since 2001, US reported measles incidence had remained below one case per one million population. Since 2004, rubella incidence has been below one case per 10 million population, and CRS incidence had been below one case per 5 million births. “Eighty-eight percent of measles cases and 54%of rubella cases were internationally imported or epidemiologically or virologically linked to importation”, the report said. The editorial author wrote that many measles outbreaks could be traced to people refusing to be vaccinated. “The single most important factor influencing decision making on childhood vaccination is the clear recommendation of a physician — clinicians must recognize their responsibility in supporting early vaccination”, the author wrote.
Bypass “preferred” for multivessel CAD
CORONARY artery bypass grafting (CABG) should be the “preferred revascularization method” for most patients with multivessel coronary artery disease, according to research published in JAMA Internal Medicine. A meta-analysis of six randomised control trials involving 6055 patients directly comparing CABG and percutaneous coronary intervention (PCI) found that in patients with multivessel coronary disease, “CABG does not only lead to a dramatic reduction in repeat revascularization and [major adverse cardiac and cerebrovascular events] but also leads to a 27% reduction in long-term all-cause mortality and a 42% reduction in MIs [myocardial infarction] compared with PCI”. The researchers wrote that the benefits were observed in trials of patients with and without diabetes. They did find a trend for excess strokes with CABG, which they said was probably related to an increase in periprocedural strokes. “However, the absolute risk increase in stroke was small compared with the absolute risk reduction in mortality and MI, as demonstrated by the numbers needed to treat”, they wrote. An accompanying editorial said a limitation of the research was that only one of the six studies included a medical therapy arm, which showed no statistical difference between CABG and medical therapy on 5-year mortality, although acute MIs were more common in the medical therapy arm. “Now we need to ensure that our studies and our patient discussions include all the viable treatment options”, the editorial said.
Kidney injury a major cardio risk factor
VETERANS who develop acute kidney injury (AKI) during hospitalisation for myocardial infarction (MI) have worse outcomes than those who have either AKI or MI alone, according to research published in the Clinical Journal of the American Society of Nephrology. The researchers analysed medical records of 36 980 veterans hospitalised between 1999 and 2005, with a mean age of 66.8 years. They found that death occurred most often for patients with both MI and AKI (57.5%), and least often (32.3%) for those with uncomplicated MI admission. “In both the unadjusted and adjusted time to event analyses, patients with AKI and AKI + MI had worse [major adverse reno-cardiovascular event] outcomes when compared to MI alone [adjusted, 1.37 (1.32-1.42) and 1.92 (1.86-1.99), respectively]”, they wrote. The data “strengthens and further delineates evidence linking AKI, and its severity in hospitalized patients either as a primary diagnosis, or in association with other critical illness such as MI, to increased long-term mortality” and composite adverse outcomes. “Furthermore, poor outcomes associated with AKI exceed those of an MI, a disease that carries a much higher public health profile, and whose prevention attracts very high levels of government and non-governmental funding”, they wrote. Prevention and therapy of AKI, as well as follow-up surveillance of this high-risk group “is urgently required”.
Long-term risks after suicide attempt
YOUNG people who attempt suicide should have long-term follow-up and supportive care in the years after their attempt as mental health problems are likely to persist, according to research published in JAMA Psychiatry. Among a longitudinal cohort of 1037 people born in Dunedin, New Zealand, in 1972 and 1973, 91 participants were known to have attempted suicide before the age of 24 years. Assessments were carried out at birth and 11 times between ages 3 and 32 years, with the most recent assessment (95% of participants) at 38 years. “Approaching midlife, young suicide attempters had more mental health problems than did nonattempters”, the researchers wrote. “They were 2 times more likely to have persistent episodes of major depression and had persistent problems with substance dependence. They also required more mental health–related services: they were more likely to seek help for psychiatric problems, to take psychiatric medications, and to have been hospitalized for a psychiatric condition.” They found suicidal behaviour also remained common, with more than 20% of young suicide attempters reporting additional suicide attempts between ages 26 and 38 years, a threefold difference compared with non-attempters. Suicide attempters were also in “significantly worse physical health as they approached midlife”. “High rates of suicidal behavior are likely to persist with the ongoing global recession. In an era of economic stress and scarce financial resources, young suicide attempters may be an important target for intervention and secondary prevention services”, the researchers wrote.
Anaesthetic trainees at risk of substance misuse
DESPITE considerable attention paid to the issue of substance use disorder (SUD) among anaesthetists in the US, there is no evidence the incidence and outcomes of SUD has improved over time, according to research published in JAMA. In a retrospective cohort study of 44 612 doctors who began anaesthesiology residency programs in the US between 1975 and 2009, the researchers found 0.86% had evidence of SUD during training. The risk of relapse during the follow-up period to the end of 2010 was high, indicating persistence of risk after training. “Risk of death was also high; at least 11% of those with evidence of SUD died of a cause directly related to SUD”, the researchers wrote. They found 384 study participants had evidence of SUD during training, with an overall incidence of 2.16 (95% CI, 1.95-2.39) per 1000 resident-years — 2.68 [95% CI, 2.41-2.98] in men and 0.65 [95% CI, 0.44-0.93] in women. “During the study period, an initial rate increase was followed by a period of lower rates in 1996-2002, but the highest incidence has occurred since 2003 (2.87 [95% CI, 2.42-3.39] per 1000 resident-years). The most common substances involved were intravenous opioids, followed by alcohol, marijuana or cocaine, anaesthetics/hypnotics, and oral opioids.” Because comparable published information was not available for other physician specialties, “it is difficult to determine whether SUD is of special concern to anesthesiologists or is merely representative of the larger physician issue”, the researchers wrote.